Intervals Cheat Sheet

What is Intervals?

Handle overlapping ranges and scheduling problems.

Template Code

def insert(intervals: List[List[int]], newInterval: List[int]) -> List[List[int]]:
    result = []
    i = 0
    n = len(intervals)
    
    # Phase 1: Add intervals ending before newInterval starts
    while i < n and intervals[i][1] < newInterval[0]:
        result.append(intervals[i])
        i += 1
    
    # Phase 2: Merge overlapping intervals
    while i < n and intervals[i][0] <= newInterval[1]:
        newInterval[0] = min(newInterval[0], intervals[i][0])
        newInterval[1] = max(newInterval[1], intervals[i][1])
        i += 1
    result.append(newInterval)
    
    # Phase 3: Add remaining intervals
    while i < n:
        result.append(intervals[i])
        i += 1
    
    return result

Complexity

Common Variations

• Basic Intervals
• Intervals with constraints
• Optimized Intervals

Practice Problems